said by NetFixer:
Well, since you do seem to have the MS TCPIP6 protocol installed and enabled, I have no definite explanation for why you are not at least seeing a link local [fe00::xx:xx:xx:xx] IPv6 address for that NIC. I don't think that you have a chance for getting IPv6 connectivity until you get that resolved.
I would agree with this.. You need to see the FE80 before IPv6 will work, it is how all the starting traffic works..
Link-local IPv6 Address . . . . . : fe80::708a:eeee:5566:1234%12
Maybe uninstall the stack and reinstall it, what OS was this on?